Rookie Ryan Mathews could be the fantasy acquisition to save your team.

We're at week six of the NFL season, and now is the time when some wheeling and dealing could potentially save your fantasy football team. There's some underachieving players out there that other owners in your league may be willing to trade, and there may be some overachievers on your team that you could get a lot for in return now before they revert back to their expected form.

So, I present you with some players to buy low and sell high on, something I've never done on here. I'd appreciate any feedback, and feel free to share your own candidates. Also, I'll have the week six fantasy football roundup for you over the next few days, so make sure to check back for that.

Buy Low

QB

Ben Roethlisberger(Pittsburgh Steelers)Stats: N/AQB Rank: N/AFantasy Points: N/AHe's back, he apparently looks great in practice, and he was the #9 fantasy quarterback in 2009. With targets such as Mike Wallace, Hines Ward, and Heath Miller, he should be every bit as good in 2010.

Reports are that Cutler will be good to go in week six after missing week five and much of week four due to a concussion. Due to a horrible performance by him and the Bears' offensive line on national television in week four(before he left with the concussion), some people are down on Cutler's prospects for the rest of the season.

Should there be a big concern with Cutler? For real football, sure. The Bears' offensive line is a disaster, just like it was in 2009. And Cutler's still making some very questionable decisions. But for fantasy football, he's still going to be "top-10" good. In this Mike Martz offense, he's going to have 300+ yard passing games with multiple touchdowns frequently. Yeah, he's going to have interceptions as well, but those are only negative-2 points.

In week five, Jones got over 10 touches for the first time of the season. He did well with those touches too, running for 109 yards on 15 carries, and adding four catches for 17 yards. It appears he may now even be the main back in Dallas ahead of Marion Barber:

"We need to get Felix the ball more,'' Phillips said today. ``We did that, and I thought it showed up well. We'll continue to evaluate what we need, but I thought it helped our running game.''

Jones is a highly explosive back that has averaged 6.3 yards per carry over his career. He's capable of putting up some huge numbers, and if the Cowboys are going to give him the ball, he very well may do so.Knowshon Moreno(Denver Broncos)Stats: 39 Carries, 111 Yards, 2 Touchdowns; 5 Receptions, 71 Yards.Fantasy Points: 29RB Rank: #29

Moreno is expected to return in week six, and will immediately be the Broncos' #1 back. They're desperately looking to improve the run game, so we should be seeing a heavy dose of Moreno for the rest of the year. He's annoyed fantasy owners, and his hamstring injury may understandably have his owners concerned, so you may be able to get him at a cheap price.

The rookie's been bothered by a high ankle sprain, and he's had to battle Mike Tolbert to win the starting job back. Well, Norv Turner's now saying he has. Mathews is an extremely talented running back that could be the kind of guy that could turn your fantasy team around the second half. There's a ton of upside here, and at worst he's going to give you solid numbers as a starting running back that can catch the ball too.

Jennings is 32nd in wide receiver targets this year, after having over 1,100 receiving yards in 2009. He's healthy, and reports are that the coaching staff wants him to get the ball more, so expect it to happen. With a great quarterback in Aaron Rodgers, Jennings can put up some monster weeks.Johnny Knox(Chicago Bears)Stats: 13 Receptions, 272 Yards, 0 Touchdowns.Fantasy Points: 25WR Rank: #48

Knox is the #1 Bears receiver and a perfect fit in Mike Martz's offense. He's a big play threat as well with his 4.3 speed, and it's evident in his 20.9 yards per catch, which ranks third in the NFL. He and Jay Cutler are going to connect on some bombs this year. After catching just two passes over the last two weeks, some fantasy owners may be ready to give up on him. If you're looking for an upgrade for your second or third receiver without having to give up too much, Knox would be a great acquisition.Mike Wallace(Pittsburgh Steelers)Stats: 9 Receptions, 211 Yards, 2 Touchdowns.Fantasy Points: 32WR Rank: #36

Wallace's numbers will return, perhaps greatly with the return of Big Ben. He's a speedy receiver that can make the big plays, which Charlie Batch and Dennis Dixon didn't really give him the chance to do so. That will change with Roethlisberger.

The rookie out of Florida is part of the reason the Patriots felt they could afford to deal Randy Moss. He has 17 catches over his last three games, and it's only a matter of time before he finds the end zone. Having a great quarterback in Tom Brady doesn't hurt either.

Orton's start hasn't been a fluke, and I'm not saying he still won't be good. He's a great fit for Josh McDaniels' offense, and has a good chemistry going with many receivers(Brandon Lloyd, Eddie Royal, Jabar Gaffney, Demaryius Thomas), making it difficult for defenses to gameplan for the Broncos' passing attack. But, I think his value's at its peak right now, and have my doubts as to whether he'll finish the season as a top-10 fantasy quarterback, even though he's currently ranked third at the position.

Second-year running back Knowshon Moreno will return soon(or so we keep hearing), and the Broncos absolutely need to establish the run. They currently rank last in the league in rushing yards(259) and yards per carry(2.3... yikes).

Over the last three games, Orton's thrown for 1,131 yards(377 yards per game). Pretty damn impressive. However, the Broncos are 1-2 in those three games with a negative-22 point differential. Not so impressive. They must get a balanced offensive attack if they want to win games.

Orton will do fine, but I just don't expect these gaudy passing numbers to continue. If they do, that's probably not going to be good news for the Broncos' playoff hopes.

Don't go handing Orton away, but you may be able to get that guy in your league that knows nothing about the players to give you quite a nice return.

Sanchez has been incredibly efficient in the early going with his eight touchdowns and no interceptions. However, he's still looked erratic at times, like last night when he completed just 21 of 44 passes against the Vikings.

More importantly, the Jets are finding out how good their run game is. They're currently averaging a whopping 165.2 yards per game on the ground, by far the best in the NFL. 31-year-old LaDainian Tomlinson looks better than he has in a few years, as he's averaging 5.7 yards per carry with three touchdowns. Shonn Greene's looked great over the last two weeks as well.

When you have the league's best run game and one of the best run defenses, why force your second-year quarterback to throw the ball 30+ times?

This really isn't selling "high" on a guy that was projected to be a top-10 back coming into the season, but his team, and especially quarterback situation, is so terrible that he isn't going to get many carries or lanes to run through when he does. The Panthers are going to be playing from behind in most every game, but teams will still put eight in the box because rookie quarterback Jimmy Clausen has not shown that he can effectively throw the ball yet. Let's not forget DeAngelo still has a very good back behind him in Jonathan Stewart that will take touches away too.

DeAngelo's a great back and still averaging a very nice 4.7 yards per carry, but he's just in a terrible situation right now to be the premier fantasy option he can be. Still, there might be somebody in your league that believes otherwise. Dangle him.Jonathan Stewart(Carolina Panthers)Stats: 36 Carries, 119 Yards, 1 Touchdown; 4 Receptions, 77 Yards, 1 Touchdown.Fantasy Points: 27Position Rank: #33

Do I really need to bother(READ ABOVE!)? Okay, I caved. Try to trade Stewart away for anything useful, because he's unlikely to be the rest of the season for the reasons I said with DeAngelo Williams, especially when Stewart's #2 on the Panthers' running back depth chart. He hasn't had more than eight carries in a game this year, and is just averaging 3.3 yards per carry anyway.Michael Bush(Oakland Raiders)Stats: 36 Carries, 157 Yards, 2 Touchdowns; 5 Receptions, 47 Yards, 0 Touchdowns.Fantasy Points: 31RB Rank: #27

Bush is coming off of a 19-point fantasy performance where he had 28 touches, but that's thanks to Darren McFadden's hamstring injury. McFadden sounds iffy for week six, but will be the #1 running back when he returns.

The Steelers threw for 4,148 yards in 2009, good for ninth in the NFL. In 2010, they're averaging 136 passing yards per game, which is last in the NFL.

Mendenhall is averaging 22.3 rushing attempts per game in 2010. He averaged just 15.1 carries in 2009.

The Steelers, with Roethlisberger, are not the running team of the past. They're a pass-first team. And reports are that Roethlisberger's looked terrific in practice.

Mendenhall's still going to put up solid numbers and find the end zone, but his touches are likely to go down. If you're loaded at running back, you can fill another positional need nicely by trading him right now.

2. He's had great month-long stretches in the past, only to disappear for the rest of the season. He's been known to be lazy in practices and more or less "take plays" off in some games. The talent's always been there, as any 49ers or Bears fan will tell you. But there's a reason the 29-year-old's already on his fourth team.

3. Between Lloyd, Eddie Royal, Jabar Gaffney, and Demaryius Thomas, we didn't know who would be the #1 receiver. Actually, coming into the season, Lloyd might appear to be #4 out of those guys. After three 115+ yard receiving performances, he's basically the #1 now, and opposing teams will begin treating him that way. He's not going to sneak up on anybody. Over these next three weeks he'll go up against Darrelle Revis/Antonio Cromartie and the Jets, Nnamdi Asomugha and the Raiders, and Nate Clements and the 49ers. Those matchups are going to be tough for any receiver.

4. Demaryius Thomas. The Broncos love their 6'3", 230-pound rookie, and he's their planned replacement for Brandon Marshall. He put his talents on display in week two, when he had eight catches, 97 yards receiving, and a touchdown. If his neck injury suffered in week five isn't serious, he should become a bigger part of the Broncos' passing game, especially in the red zone.Braylon Edwards(New York Jets)Stats: 17 Receptions, 297 Yards, 3 Touchdowns.Fantasy Points: 47WR Rank: #12

1. Read what I said about Mark Sanchez.

2. Santonio Holmes was targeted nine times by Mark Sanchez in his first game of the season. That's a huge kick in the nuts for Braylon Edwards owners. Holmes' role will continue to grow, and the Edwards targets will lessen.Terrell Owens(Cincinnati Bengals)Stats: 31 Receptions, 476 Yards, 2 Touchdowns.Fantasy Points: 58WR Rank: #7

Second all-time in receiving yards, third all-time in receiving touchdowns, and fifth all-time in receptions. He has 17 receptions, 324 yards receiving, and two touchdowns over his last two games. So why in the hell would you consider trading him right now? Two reasons:

1. I still think Ochocinco is targeted more, and probably even finishes with better numbers on the season.

2. Carson Palmer's looked terrible, and the Bengals would be wise to use Cedric Benson and their running game more.

It's going to be tough to find a biter for Marcedes Lewis, but those five touchdowns are pretty appealing for a position that's very tough to find fantasy points. The five touchdowns have come over just 16 catches though, or one touchdown for about every three interceptions. In Lewis' previous four seasons, he never had over two touchdowns in a single season. Good luck keeping this pace up.